Fig. 2

Macroscopic and histopathological findings of the resected specimen. a The lateral segment consists of a solid mass. b, c Hematoxylin-eosin staining shows the enlarged nuclei and condensed chromatin of the tumor cells. d–g Immunopathological examination. The tumor cells are positive for CD56 (d), synaptophysin (e), and chromogranin A (f). Ki-67 was positive in > 90% of the tumor cells (g)